# -*- coding: UTF-8 -*-
__all__ = ['IpTable', 'InvereIpTable', 'createSubKey',
           'E_extend', 's_box_change', 'p_box_change',
           'xor', 'string2bin', 'bin2string']


# 初始IP置换表
def IpTable(text):
    IP = [58, 50, 42, 34, 26, 18, 10, 2,
          60, 52, 44, 36, 28, 20, 12, 4,
          62, 54, 46, 38, 30, 22, 14, 6,
          64, 56, 48, 40, 32, 24, 16, 8,
          57, 49, 41, 33, 25, 17, 9, 1,
          59, 51, 43, 35, 27, 19, 11, 3,
          61, 53, 45, 37, 29, 21, 13, 5,
          63, 55, 47, 39, 31, 23, 15, 7]
    return [text[IP[i] - 1] for i in range(64)]


# 逆初始IP置换表
def InvereIpTable(text):
    INVERSE_IP = [40, 8, 48, 16, 56, 24, 64, 32,
                  39, 7, 47, 15, 55, 23, 63, 31,
                  38, 6, 46, 14, 54, 22, 62, 30,
                  37, 5, 45, 13, 53, 21, 61, 29,
                  36, 4, 44, 12, 52, 20, 60, 28,
                  35, 3, 43, 11, 51, 19, 59, 27,
                  34, 2, 42, 10, 50, 18, 58, 26,
                  33, 1, 41, 9, 49, 17, 57, 25]

    return [text[INVERSE_IP[i] - 1] for i in range(64)]


# E扩展置换
def E_extend(text):
    E = [32, 1, 2, 3, 4, 5,
         4, 5, 6, 7, 8, 9,
         8, 9, 10, 11, 12, 13,
         12, 13, 14, 15, 16, 17,
         16, 17, 18, 19, 20, 21,
         20, 21, 22, 23, 24, 25,
         24, 25, 26, 27, 28, 29,
         28, 29, 30, 31, 32, 1]
    return [text[E[i] - 1] for i in range(48)]


# PC_1变换和PC_2变换
PC_1 = [57, 49, 41, 33, 25, 17, 9,
        1, 58, 50, 42, 34, 26, 18,
        10, 2, 59, 51, 43, 35, 27,
        19, 11, 3, 60, 52, 44, 36,
        63, 55, 47, 39, 31, 23, 15,
        7, 62, 54, 46, 38, 30, 22,
        14, 6, 61, 53, 45, 37, 29,
        21, 13, 5, 28, 20, 12, 4]

PC_2 = [14, 17, 11, 24, 1, 5,
        3, 28, 15, 6, 21, 10,
        23, 19, 12, 4, 26, 8,
        16, 7, 27, 20, 13, 2,
        41, 52, 31, 37, 47, 55,
        30, 40, 51, 45, 33, 48,
        44, 49, 39, 56, 34, 53,
        46, 42, 50, 36, 29, 32]

S1 = [[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7],
      [0, 15, 7, 4, 15, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8],
      [4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0],
      [15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13]]

S2 = [[15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10],
      [3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5],
      [0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15],
      [13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9]]

S3 = [[10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8],
      [13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1],
      [13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7],
      [1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12]]

S4 = [[7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15],
      [13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9],
      [10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4],
      [3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14]]

S5 = [[2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9],
      [14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6],
      [4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14],
      [11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3]]

S6 = [[12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11],
      [10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8],
      [9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6],
      [4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13]]

S7 = [[4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1],
      [13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6],
      [1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2],
      [6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12]]

S8 = [[13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7],
      [1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2],
      [7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8],
      [2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11]]


S_box = [S1, S2, S3, S4, S5, S6, S7, S8]


def move(text, times):
    return text[times:] + text[:times]


# 子密钥的生成
def createSubKey(preKey):
    result = []
    key56 = [preKey[PC_1[i]-1] for i in range(56)]  # 对56个非校验位进行PC_1置换

    step = [1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1]  # 移动的步长

    for i in range(16):
        key_left = move(key56[:28], step[i])
        key_right = move(key56[28:], step[i])
        key56 = key_left + key_right
        key48 = [key56[PC_2[i]-1] for i in range(48)]
        result.append(key48)
    return result


def dec2bin4(dec):
    return '{:04b}'.format(dec)


def dec2bin8(dec):
    return '{:08b}'.format(dec)


# s盒置换，将48位输入均分成长度为6的8个小组，每个小组按顺序进入相应的S盒各得到4位输出，返回合并后的32位结果。
def s_box_change(text):
    result = []
    for i in range(0, 8):
        temp = text[i*6:(i+1)*6]
        row = int(str(temp[0])+str(temp[-1]), 2)
        col = int(str(temp[1])+str(temp[2])+str(temp[3])+str(temp[4]), 2)
        message = S_box[i][row][col]
        result.append(dec2bin4(message))

    return [int(x) for x in ''.join(result)]


# P-盒置换：将32位输入按 P 规则置换后返回32位结果。
def p_box_change(text):
    P = [16, 7, 20, 21, 29, 12, 28, 17,
         1, 15, 23, 26, 5, 18, 31, 10,
         2, 8, 24, 14, 32, 27, 3, 9,
         19, 13, 30, 6, 22, 11, 4, 25]

    return [text[P[i] - 1] for i in range(32)]


# 异或操作, 对序列进行各位异或操作，并返回所有结果
def xor(m, n):
    return [a ^ b for a, b in zip(m, n)]


def char2bin(char):
    # 返回一个（ASCII）字符的8位二进制表示
    b = bin(ord(char)).replace('0b', '')
    space = 8 - len(b)
    return '0' * space + b


def string2bin(text):
    # 将含有8个字符的字符串转化成包含64位二进制数字的列表。
    
    if len(text) != 8:
        return False
    temp = [char2bin(char) for char in text]
    return [int(number) for number in ''.join(temp)]


def bin2string(text):
    # 将包含64位二进制数字的列表转化成含有8位字符的字符串。
    if len(text) != 64:
        return False
    text = [str(number) for number in text]  # 先将列表里的 int 类型转化为 str 类型
    result = []
    for i in range(8):
        binstring = ''.join(text[i * 8:i * 8 + 8])
        result.append(chr(int(binstring, 2)))
    return ''.join(result)



